Preparation of (Lu,Y) ₃(Al,Sc,Cr) ₂Al ₃O ₁₂ phosphor ceramics with high thermal stability for near-infrared LED/LD

Abstract

Near-infrared (NIR) phosphor-converted light-emitting diodes/laser diodes (LEDs/LDs) are prospective lighting sources for NIR spectroscopy. However, developing a NIR phosphor material with desired thermal robustness and high photoelectric efficiency is a crucial challenge for its applications. In this work, based on the cationic radius matching effect, a series of (Lu,Y)₃(Al,Sc,Cr)₂Al₃O₁₂ NIR phosphor ceramics (LuYScCr NIR-PCs) were fabricated via vacuum sintering. An excellent thermal stability (95%@150 ^oC) was obtained in the prepared NIR-PC, owing to its weak electron phonon coupling effect (small Huang Rhys factor). Being excited at 460 nm, the NIR-PCs realized a broadband emission (650-850 nm) with an IQE of 60.68 %. Combining NIR-PCs with LED/LD chips, the maximum output power of the encapsulated LED prototype was 447 mW @ 300 mA with a photoelectric efficiency of as high as 18.6 % @ 180 mA, and the maximum output power of the LD prototype was 814mW @ 2.5 A. The working temperatures of the NIR-PCs were 70.8 ^oC @ 300 mA (LED) and 102.8 ^oC @ 3 A (LD), respectively. Finally, the prepared NIR-PCs applied in the food detection were verified in this study, demonstrating its anticipated application prospects in the future.